A glaring contrast on Iran among Clinton, Trump and Cruz

On Wednesday morning in Washington, a hoarse Hillary Clinton delivered a poised and methodical explanation of her decision to support the Iran nuclear deal inside the staid and climate-controlled confines of the buttoned-up Brookings Institution.

Three miles away and three hours later, under a baking sun on the west lawn of the U.S. Capitol, Sen. Ted Cruz of Texas and Donald Trump stood on a stage and railed against the same accord using apocalyptic language and stirring the emotions of a pugilistic tea party crowd that still detests Republican leadership as much as it does President Barack Obama.

The gap between the trio of 2016 presidential contenders on the most contentious foreign policy issue since the 2003 decision to invade Iraq was vast, not only in their positions, but in their presentations, provocations and knowledge of the topic.

Clinton, while supportive, recognized the skepticism of the deal's opponents, answered their concerns head-on with detailed responses in her speech and emphasized what she posited would be her ruthless enforcement of the agreement. She also blasted Republicans for their "unserious" critiques of the deal negotiated with a half dozen other world powers.

"Several Republican candidates boast that 'I'll tear up this agreement in 2017', more than a year after it's been implemented. That's not leadership. That's recklessness," said the former secretary of state.

Trump made unrealistic promises -- like guaranteeing the return of four American hostages in Iran before he even takes office -- and then returned to his typical stump speech of colorful insults and lamenting America's dire position in the world.

"All of these countries are going to do business with Iran, they're going to make lots of money and lots of other things with Iran and we're going to do and we're going to get nothing," he said. "We're led by very, very stupid people."

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Cruz's speech was tightly constructed, comprehensive and touched on more of the minutiae than Trump -- for instance, he named all four of the American prisoners and argued Senate Majority Leader Mitch McConnell and House Speaker John Boehner still had the legal authority to halt its implementation -- but his outline of the consequences of the deal were even more harrowing than Trump's. He questioned whether Democrats supporting it valued the safety and security of the United States and said any credible candidate for president should pledge to tear the deal up on his or her first day in office, a move Trump has even resisted.

"If you vote to send billions of dollars to jihadists who have pledged to murder Americans, then you bear direct responsibility for the murders carried out with the dollars you have given," Cruz said to cheers. "You cannot wash your hands of that blood."

While a Pew poll indicates just a fifth of the country supports the nuclear agreement with Iran, even more -- 30 percent -- have no opinion at all, an indication that the issue holds more resonance with party elites and foreign policy wonks in the northeast corridor than average voters in the heartland.

Clinton's address was most important because it displayed her readiness to be commander-in-chief. She framed the deal not as a triumphant victory but rather as the best of undesirable options with a brutal state sponsor of terrorism. Iran was racing toward nuclear capacity; this will erect roadblocks to that capability for more 15 years and hand America more leverage if Iran cheats, Clinton argued.

"My starting point will be one of distrust. My approach will be distrust and verify," she said, adjusting President Ronald Reagan's famous phrase in dealing with the Soviet Union.

In a vivid display of her nuance and precision, she conceded that one provision that could leave the international community without access to some of Iran's nuclear facilities for up to 24 days was troubling.

"I'd be the first to say that this part of the deal is not perfect," Clinton said.

But she noted that even delayed inspections are better than no inspections since experts say microscopic nuclear particles are detectable for years.

She spent the second half of her remarks professing her unfettered allegiance to Israel, promising to arm the U.S. ally with some of the nation's most sophisticated airpower, the F-35, as well as the strongest air defense system. She'd roll out the carpet at the White House for the Israeli Prime Minister in the first month of her presidency.

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BALTIMORE, MD - APRIL 10: Democratic presidential candidate Hillary Clinton holds a campaign rally at City Garage April 10, 2016 in Baltimore, Maryland. Voters will head to polling places for Maryland's presidential primary April 26. (Photo by Chip Somodevilla/Getty Images)

Democratic U.S. presidential candidate Hillary Clinton laughs as she listens to Representative Steve Israel (D-NY) speak on a gun control panel in Port Washington, New York April 11, 2016. REUTERS/Lucas Jackson

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BOSTON, MA - Former Secretary of State Hillary Clinton speaks to supporters at the Old South Meeting Hall during a rally in Boston, Massachusetts on Monday February 29, 2016. (Photo by Melina Mara/The Washington Post via Getty Images)

MINNEAPOLIS, MN - MARCH 01: Democratic presidential candidate former Secretary of State Hillary Clinton greets patrons at Mapps Coffee on March 1, 2016 in Minneapolis, Minnesota. Hillary Clinton is campaigning in Minnesota as Super Tuesday voting takes place in 12 states. (Photo by Justin Sullivan/Getty Images)

MOUNT VERNON, IOWA - OCTOBER 7: Former Secretary of State Hillary Clinton speaks to voters during an outdoor town hall meeting at Cornell College in Mount Vernon, Iowa on Wednesday October 7, 2015. (Photo by Melina Mara/The Washington Post via Getty Images)

MUSCATINE, IOWA - OCTOBER 6: Former Secretary of State Hillary Clinton speaks to a voter before leaving a farm in Muscatine, Iowa on Tuesday October 6, 2015. (Photo by Melina Mara/The Washington Post via Getty Images)

MANCHESTER, NH - OCTOBER 05: Democratic presidential candidate Hillary Rodham Clinton holds a town hall meeting at the Manchester Community College on October 5, 2015 in Manchester, New Hampshire. Clinton spoke about the need for gun control on the wake of a mass shooting at another community college in Oregon. (Photo by Alfredo Sosa/The Christian Science Monitor via Getty Images)

DAVIE, FL - OCTOBER 02: Democratic presidential candidate Hillary Clinton speaks about gun control during her campaign stop at the Broward College Ã Hugh Adams Central Campus on October 2, 2015 in Davie, Florida. Hillary Clinton continues to campaign for the nomination of the Democratic Party as their presidential candidate. (Photo by Joe Raedle/Getty Images)

MANCHESTER, NH - SEPTEMBER 19: Democratic presidential candidate Hillary Clinton claps on stage during the New Hampshire Democratic Party Convention at the Verizon Wireless Center on September 19, 2015 in Manchester, New Hampshire. Challenger for the democratic vote Sen. Bernie Sanders (I-VT) has been gaining ground on Clinton in Iowa and New Hampshire. (Photo by Scott Eisen/Getty Images)

PORTLAND, ME - SEPTEMBER 18: Hillary Clinton brings her Democratic presidential campaign to Maine for the first time, speaking at King Middle School. Clinton is welcomed as she is introduced at the event. (Photo by Derek Davis/Portland Press Herald via Getty Images)

CEDAR RAPIDS, IA - SEPTEMBER 7: Democratic Presidential hopeful Hillary Clinton takes time to meet supporters and take photos at the Annual Hawkeye Labor Council AFL-CIO Labor Day picnic on September 7, 2015 at Hawkeye Downs in Cedar Rapids, Iowa. Clinton spent a busy Labor Day weekend in Iowa, meeting supporters throughout the state while trying to maintain a lead over Bernie Sanders for the Democratic nomination. (Photo by David Greedy/Getty Images)

US Democratic presidential candidate Hillary Clinton takes part in a discussion after speaking about the Iran nuclear deal at the Brookings Institution in Washington, DC, on September 9, 2015. Clinton expressed firm support for the nuclear accord with Iran, calling it flawed but still strong. Clinton added that the agreement must be strictly enforced and said that if elected president next year, she would not hesitate to use military force if Iran fails to live up to its word and tries to develop a bomb. AFP PHOTO/NICHOLAS KAMM (Photo credit should read NICHOLAS KAMM/AFP/Getty Images)

PORTSMOUTH, NH - SEPTEMBER 5: Democratic presidential candidate Hillary Clinton and U.S. Senator Jeanne Shaheen take an off the schedule stop in the River Run Bookstore before shaking hands with onlookers on September 5, 2015 in Portsmouth, New Hampshire. (Photos by Charles Ommanney/The Washington Post via Getty Images)

PORTSMOUTH, NH - SEPTEMBER 5: Democratic Presidential candidate Hillary Clinton walks downtown Portsmouth and takes pictures with people September 5, 2015 in Portsmouth, New Hampshire. Clinton attended a Women for Hillary event at Portsmouth High School earlier in the day and received an endorsement from U.S. Senator Jeanne Shaheen (D-NH). (Photo by Darren McCollester/Getty Images)

LAS VEGAS, NEVADA - AUGUST 18: Former Secretary of State Hillary Clinton answers questions from journalists after speaking to north Las Vegas voters at a town hall meeting in Las Vegas, on Tuesday, August 18, 2015. The former Secretary was answering questions about emails sent and received a private server system, now in question, while she was the Secretary of State. (Photo by Melina Mara/The Washington Post via Getty Images)

UNITED STATES - August 15: Democratic presidential candidate Hillary Rodham Clinton greets fairgoers as she tours the Iowa State Fair in Des Moines, Iowa, on Saturday, August 15, 2015. (Photo By Al Drago/CQ Roll Call)

CARROLL, IA - JULY 26: Democratic presidential hopeful and former Secretary of State Hillary Clinton speaks to guests gathered for a house party on July 26, 2015 in Carroll, Iowa. Although Clinton leads all other Democratic contenders, a recent poll had her trailing several of the Republican candidates in Iowa. (Photo by Scott Olson/Getty Images)

CHICAGO, IL - MAY 20: Democratic presidential hopeful and former Secretary of State Hillary Clinton arrives for a meeting with parents and child care workers at the Center for New Horizons on May 20, 2015 in Chicago, Illinois. Clinton arrived in Chicago after campaigning Monday and Tuesday in Iowa. (Photo by Scott Olson/Getty Images)

LAS VEGAS, NV - MAY 05: Democratic presidential candidate and former U.S. Secretary of State Hillary Clinton (C) poses with students and faculty after speaking at Rancho High School on May 5, 2015 in Las Vegas, Nevada. Clinton said that any immigration reform would need to include a path to 'full and equal citizenship.' (Photo by Ethan Miller/Getty Images)

NEW YORK, NY - APRIL 23: Hillary Rodham Clinton (L) and actress Maggie Gyllenhaal attend the 2015 DVF Awards at United Nations on April 23, 2015 in New York City. (Photo by Michael Stewart/FilmMagic)

NEW YORK, NY - APRIL 29: Democratic presidential hopeful and former Secretary of State Hillary Clinton speaks during the David N. Dinkins Leadership and Public Policy Forum at Columbia University April 29, 2015 in New York City. Clinton addressed the unrest in Baltimore, called for police body cameras and a reform to sentencing. (Photo by Kevin Hagen/Getty Images)

Hillary Clinton announced her campaign for president on Sunday April, 12, 2015 with a video on YouTube.

(Screenshot from YouTube)

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Even in support of this Iran deal, Clinton's hawkish wings were apparent.

"I will not hesitate to take military action if Iran attempts to obtain a nuclear weapon," she said. "We will act decisively if we need to."

The atmosphere in the shadow of the Capitol dome was far less subtle.

A litany of comparisons were apocalyptic: Of Iran's leadership to Hitler, of Obama to the appeasement of Neville Chamberlain, of the prospect of a nuclear attack on American soil that would dwarf the Sept. 11 attacks in terms of casualties.

An elderly woman held a sign that read: "Potus in bed with those who behead." Another man's blared: "Impeach Hussein Obama, Prosecute Hillary."

Cruz fed on these fears by saying that with this deal, the Obama administration would become the world's leading financier of Islamic terrorism. He didn't leave it to the crowd's imagination.

"If this deal goes through, we know to an absolute certainty people will die," Cruz declared. "Osama bin Laden never had $100 billion."

The crowd, which booed the names of McConnell and Boehner with more fervor than Obama, ate it up. Which explains why this crowd seemed even more receptive to Cruz than Trump, who looked to be there more to soak up the raucous audience than to dive into specifics on Iran.

Clinton has endured a fair amount of turbulence as a candidate in recent weeks. But on this day, she benefited from a contrast on foreign policy with both Cruz and Trump.

They attracted the crowd and cheers in a carnival-like atmosphere; she looked like someone who knows her way around the world and the White House.